Looking for some explanation of this, we may find a key in the known customs of various Indian tribes, and the lower races of men. It is known that a tribe of Indians is divided into smaller bands, which are called gens or clans. A gens may consist of several hundred persons, but it is the unit of organization. It takes the place of a family among civilized people. These various bands are generally named after some animal. In the beginning these names may have been of no special significance, but in course of time each band would come to regard themselves as descendants of the animal whose name they bore. Hence the animal itself would be considered sacred in their eyes, and its life would seldom be taken by members of that gens. The animal thus honored by the gens was, in the Indian dialect, the totem of the clan. This organization and custom we find running all through the Indian tribes. In many tribes the Indians were wont to carve a figure of their totem on a piece of slate, or even to carve a stone in the shape of the totem, which carved or sculptured stone they wore as an ornament, or carried as a charm to ward off evil and bring them good luck.51 We need only suppose that this system was very fully developed among the Mound Builders of Wisconsin, to see what important bearing it has on these effigy mounds. A tribe located on one of the fertile river valleys of Wisconsin was composed of various gens or clans. On some common point in proximity to their villages, or some spot which commanded a wide view of the surrounding country, each gens would rear an effigy of its totem, the animal sacred to them. In every tribe some gens would be the most powerful, or for some cause the most respected, and its totem would be given in the largest effigy, and would be placed in the most commanding position. In a different locality some other tribe would be located, and some other totem would be regarded as of the most importance.